static L<GazelleTree> dm_gazelle_reasonAboutChatInput(S userName, S content, O... _) {

  bool debug = boolPar debug(_);

  bool selfVarsFix = boolPar selfVarsFix(_, true);

  GazelleEvalContext ctx = optPar ctx(_);

  if (ctx == null) ctx = dm_gazelle_stdEvalContext(dm_gazelle_allRulesWithComment(optPar requiredComment(_, "discord")));

  // Need input as first condition

  ctx.engine.dropRulesWhere(r -> cicOneOf(r.comments, "in 1 = statement", "in = statement"));

  if (debug) print("Have rules: " + collect globalID(ctx.engine.rules));

  gazelle_addHelperTablesToRules(ctx.engine);

  GazelleTree tree1 = new(ctx, content);

  L<GazelleTree> l = dm_gazelle_getChildren(tree1, firstConditionOnly := true);

  GazelleTree tree2 = new(ctx, optCurly(userName) + " says: " + content);

  l.addAll(dm_gazelle_getChildren(tree2, firstConditionOnly := true));

  if (boolPar skipBad(_, true)) l = [GazelleTree t : l | neq(t.prediction, 'bad)];

  gazelle_sortChildren(l);

  for (GazelleTree t : l)

    if (t.rule() != null) {

      RuleEngine2_MatchedRule mr = t.mr;

      LS in = t.rule().in;

      int iCond = t.mr.iCond;

      if (l(in) > iCond) {

        LS conditions = dropFirst(iCond, in);

        print("Remaining conditions for " + t.ruleID() + " with " + t.mr.map + ": " + conditions);

        new Matches m;

        if (!matchAny("in " + (iCond+1) + " = statement *", t.rule().comments, m))

          continue with print("Unwired condition");

        S subRuleID = $1;

        print("Found subrule: " + subRuleID);

        L fulfillments = dm_gazelle_fulfillmentsForRule(subRuleID);

        print("Have fulfillments:");

        for (O f : fulfillments) {

          SS varMap = asCIMap(safeUnstructMap(getString varMap(f)));

          printIndent(sfu(varMap));

          // self-vars hack to fix John Doe problem

          if (selfVarsFix) {

            S cond = first(conditions);

            for (S x : identifiersOnly(codeTokens(mr.tokenize(cond))))

              if (!varMap.containsKey(x)) {

                print("Self-linking " + x);

                varMap.put(x, x);

              }

          }

          SS newMap = mergeMapsStrictlyIC(asCIMap(t.mr.map), varMap);

          if (newMap == null)

            continue with printIndent("Can't merge maps");

          printIndent("Maps merged! => " + sfu(newMap));

          t.mr.map = newMap;

          t.mr.iCond++;

          t.mr.remainingConditions = dropFirst(t.mr.remainingConditions); // XX: also should rewrite with new vars

          t.mr.remainingConditionsWithType = dropFirst(t.mr.remainingConditionsWithType);

          t.mr.out = null;

          t.line = t.mr.outText();

          print("Rewrote " + t.mr.rule.out + " to: " + t.line);

          break;

        }

      }

    }

  // drop unsatisfied entries

  l = [GazelleTree t : l | t.mr == null || !t.mr.moreConditions()];

  ret l;

}